1-Methylcyclopropene is a gaseous product at room temperature. Due to its unsaturated properties, its chemical properties are unstable and easy to self-polymerize. In addition, as a hydrocarbon of low molecular weight, it is dangerous to explode when compressed.
To address these issues, a variety of substrates have been investigated to encapsulate 1-MCP, such as cyclodextrin (CD), calabash urea, molecular sieves, as well as modified starch and sawdust. Among them, α -Cd is considered to be a favorable substrate, because 1-MCP can stably reside in the cavity of α -Cd as a single molecule, and the formation of 1-MCP/α -Cd complex products have been commercialized.
The encapsulated 1-MCP/α -Cd complexes greatly reduce the explosive potential due to the reduced vapor pressure, and they also prevent the self-polymerization of 1-MCP, both of which simplify its treatment. Neo et al. (2007) studied the encapsulation of gaseous 1-MCP molecules into aqueous α -Cd in a closed stirred container with a flat gas-liquid interface. The molecular encapsulation of gaseous 1-McP by α -Cd is a simultaneous two-step process, including the dissolution of gaseous 1-McP and the encapsulation of dissolved 1-McP into α -Cd. The change of X-ray diffraction pattern shows that the lattice structure of α -Cd changes after adding 1-MCP.
Trotta et al. (2011) Reported the complexation ability of CD nanosponge with 1-MCP. They synthesized CD-based carbonate nanosponges from natural β-CD and active carbonyl compounds. 1-MCP contained in β-CD nanosponges showed excellent ethylene resistance in long-acting cut flowers compared to α-CD composite products, such as SmartFresh, due to the increased lumen.
Zhang et al. (2011) reported the encapsulated 1-MCP by calabash  urea. Calabash  urea is a barrel-shaped macrocyclic molecule prepared from cheap starting materials glycine urea and formalin. It has a cavity size similar to α -Cd and acts as an absorbent for encapsulated 1-MCP. The effects of encapsulation conditions on the formation of the complex, the amount of CB – encapsulated 1-MCP, the encapsulation temperature and time, and CB concentration were investigated. In addition, 1-MCP can be released from the complex in different solutions such as sodium bicarbonate, benzoic acid and distilled water.
Other packaging methods are reported in the patent literature, namely CN100364394C and CN101416658B. Patent CN100364394C discloses a microcapsule for fresh fruits, vegetables and flowers. The core material of 1-MCP consists of 0.5%~3.5%, 20%~30% wall shell 3A molecular sieve, 60%~65% starch, 1%~2% ammonium chloride and 3%~18% sodium bicarbonate. CN101416658 B disclosed another product containing 1-MCP, its composition is as follows: 1-MCP 0.15% ~ 4.8%, the modified stabilizer is made of the following raw materials, according to the weight of the preparation: 20 ~ 100 modified starch; β-CD or derivatives of 0 to 80 parts; α-CD or derivatives of 0 to 40 parts.
This post was created with our nice and easy submission form. Create your post!